The present invention relates to an image forming method wherein toner is supplied to an image forming apparatus from a toner cartridge made up of a toner storage container and a packaging container for packaging a storage container.
In the field of image forming technique using an electrophotographic process in recent years, studies have been made to develop a technique for forming an image with less power consumption to give consideration to global environment. One of such techniques has succeeded in forming an image at a fixing temperature lower than the conventional temperature by utilizing a polymerized toner or the like containing the wax of lower melting point (e.g., Patent Document 1).
When storing such toner especially in a high-temperature environment, there is a concern about a problem of blocking wherein toner particles are coagulated with one another by heat. To eliminate the possibility of causing blocking during toner storage, development efforts have been made to find out a method of accommodating and storing toner in a container characterized by excellent heat insulation.
The following describes the techniques on a toner container of excellent heat insulation. One of such techniques is exemplified by the invention wherein a toner container uses an organic expandable material as either the inner shell material and outer shell material of a thin-walled synthetic resin-made supporting member or the intermediate material of two supporting members having two-layer structure (e.g., Patent Document 2). Another example is an invention of using a toner container formed of a material having heat conductivity below a predetermined value (e.g., Patent Document 3). A further example is provided an invention wherein a plurality of plastic molded products forming the heat insulating layer are employed to produce a toner container that maintains high printing accuracy in a high-temperature environment (e.g., Patent Document 4). As described above, efforts have been made to develop the techniques for maintaining the toner quality without being affected by the environment, and achieving stable preservation.
[Patent Document 1] Unexamined Japanese Patent Application Publication No. 2001-42564
[Patent Document 2] Unexamined Japanese Patent Application Publication No. H5-341647
[Patent Document 3] Unexamined Japanese Patent Application Publication No. H6-72472
[Patent Document 4] Unexamined Japanese Patent Application Publication No. 2004-13085
The main stream in the image forming apparatus based on electrophotographic technology has been the technique wherein a toner-containing cartridge is mounted on an apparatus and toner is supplied from the mounted cartridge. The containers disclosed in the aforementioned Patent Documents 2 and 3 are intended to store and convey toner, but these documents fail to describe use of the container itself as a cartridge being mounted on the main body of the image forming apparatus. Further, the Patent Document 4 discloses a toner container used as a cartridge. In this technique, however, much time and effort have been required to manufacture a cartridge. For example, in order to form a resin layer constituting the cartridge and a heat insulating layer, a great number of molding operations has to be performed to form a sandwich structure.